Our Geo Quiz takes us to the site of the Underworld Cup of Hungary. The event attracts hundreds of mountain bikers who enjoy the thrill of racing through a maze of dark, narrow tunnels in an abandoned limestone mine on the outskirts of Hungary's capital.

Our Geo Quiz takes us to the site of the Underworld Cup of Hungary. The event attracts hundreds of mountain bikers who enjoy the thrill of racing through a maze of dark, narrow tunnels in an abandoned limestone mine on the outskirts of Hungary's capital.

Our Geo Quiz takes us to the site of the Underworld Cup of Hungary. The event attracts hundreds of mountain bikers who enjoy the thrill of racing through a maze of dark, narrow tunnels in an abandoned limestone mine on the outskirts of Hungary's capital.

Our Geo Quiz takes us to the site of the Underworld Cup of Hungary. The event attracts hundreds of mountain bikers who enjoy the thrill of racing through a maze of dark, narrow tunnels in an abandoned limestone mine on the outskirts of Hungary's capital.